1. Field of the Invention
The present invention relates to a voltage regulator, and in particular, a voltage regulator that generates an internal source voltage in either an active mode or a standby mode, a semiconductor device including the voltage regulator, and a voltage generation method for the voltage regulator.
2. Description of the Related Art
A semiconductor chip includes an internal circuit that assumes various functions and a voltage regulator that generates an internal source voltage for operating the internal circuit on the basis of a source voltage and supplies the internal source voltage to the internal circuit. The voltage regulator is provided with a differential amplification part that applies a drive voltage having a voltage value corresponding to a difference between the internal source voltage and a reference voltage to a gate terminal of an output transistor for outputting the internal source voltage in order to stabilize the voltage value of the internal source voltage regardless of load change in the internal circuit (see Japanese Patent Application Laid-Open No. 2008-310703, for example). Such a voltage regulator achieves a high-speed operation by increasing an amount of current flowed through the differential amplification part during an active mode. The voltage regulator achieves power saving by reducing an amount of current flowed through the differential amplification part during a standby mode.